Topic 3. Control flow: branching and loops

Goal: become familiar with C# selection and iteration statements; learn to use if, switch, switch expressions with patterns, and while, do/while, for, and foreach loops; master jump statements and common algorithms: accumulation, searching, repeated input prompts, and approximate calculations with a specified accuracy.

Lecture contents

1. Blocks and the conditional statement — Code blocks and scope · The if statement · The ternary operator ?:
2. switch and patterns — The switch statement · Patterns · The switch expression
3. Loops — while and do/while loops · The for loop · The foreach loop
4. Jump statements and common algorithms — Jump statements · Common loop algorithms
5. Examples and common mistakes — Example programs · Common mistakes

Practice and review

• Practice — 3 worked examples with complete code and output
• Tasks — 30 variants, each with tasks at three difficulty levels
• Summary — conclusions, self-check questions, and useful links